Shimano spends considerable time making certain that it's bottom brackets use only the best, silky-smooth bearings, advanced sealing, and high manufacturing tolerances.
Such is the case with its new Ultegra SM-BB72-41B PressFit Bottom Bracket design. Where a typical road bike has a 68 or 70mm bottom bracket shell width, a BB86-equipped frame has a shell that measures 86.5mm wide. A BB86 shell lacks internal threads and has a 41mm inside diameter.
1 - Optimum power transfer
2 - DURA-ACE proven 4-arm design: Equal stiffness and lighter weight
3 - 14 g lighter weight and half the friction of the SM-BB6700, while maintaining the same durability
Variety choice of gearing: 53-39T/52-36T/50-34T/46-36T
Weight: 77 g (SM-BBR60) 69 g (SM-BB72-41B)